Such a method is disclosed for example in U.S. Pat. No. 4,863,538. In this case the material is a powderous solid material which is applied in layers to the upper side of a lowerable piston and which is sintered at places corresponding to the object by means of a laser. For forming the successive layers the piston is stepwise lowered within a cylinder which surrounds the powderous material. A heater maintains the material at an operating temperature of about 150.degree. C. as required for the sintering process.
This known method has the drawbacks that together with the material also the cylinder must be heated up to the operating temperature which requires a preheating time of 2 to 3 hours. Moreover, before removing the object from the cylinder a slow cooling down to below 100.degree. C. must be carried out in order to avoid the risk of dust explosion. During this cool-down period the object must remain within the cylinder. In summary, the known method results in long rigging and strip-down times and therefore long production times. This drawback shall be eliminated with the invention.